The additional memory settings control how the memory manager on the host system swaps virtual machines out of physical RAM.

To configure additional memory settings, select Edit > Preferences > Memory.

Table 1. Additional Memory Settings
Setting Description
Fit all virtual machine memory into reserved host RAM Select this option to impose the tightest restrictions on the number and memory size of virtual machines that can run at a given time. Because the virtual machines are running entirely in RAM, they have the best possible performance.
Allow some virtual machine memory to be swapped The host operating system can swap a moderate amount of virtual machine memory to disk. Select this setting to allow the number or memory size of virtual machines to be increased so that they can run on the host system at a given time.

This setting might result in reduced performance if virtual machine memory must be shifted between RAM and disk.

Allow most virtual machine memory to be swapped The host operating system can swap as much virtual machine memory to disk as necessary. When this setting is selected, you can run more virtual machines with more memory than when the Allow some virtual machine memory to be swapped setting is selected.

This setting might result in reduced performance if virtual machine memory must be shifted between RAM and disk.